package calculations;

/**
@version 1.20 2004-02-10
@author Cay Horstmann
*/

import java.math.*;
import java.util.*;

public class BigIntegerTest
{  
public static void main(String[] args)
{  
   Scanner in = new Scanner(System.in);

   System.out.print("How many numbers do you need to draw? ");
   int k = in.nextInt();
   
   System.out.print("What is the highest number you can draw? ");
   int n = in.nextInt();

   /* 
      compute binomial coefficient
      n * (n - 1) * (n - 2) * . . . * (n - k + 1)
      -------------------------------------------
      1 * 2 * 3 * . . . * k
   */

   BigInteger lotteryOdds = BigInteger.valueOf(1);

   for (int i = 1; i <= k; i++)
      lotteryOdds = lotteryOdds
         .multiply(BigInteger.valueOf(n - i + 1))
         .divide(BigInteger.valueOf(i));

   System.out.println("Your odds are 1 in " + lotteryOdds + ". Good luck!");
}
}

